Council of Scientific and Industrial Research - National Botanical Research Institute (CSIR-NBRI), Lucknow 226001, India; Amity Institute of Environmental Sciences, Amity University, Noida, India.
J Hazard Mater. 2013 Nov 15;262:1123-31. doi: 10.1016/j.jhazmat.2012.06.049. Epub 2012 Jul 1.
Carcinogenic arsenic (As) concentrations are found in rice due to irrigation with contaminated groundwater in South-East Asia. The present study evaluates comparative antioxidant property and specific amino acid accumulation in contrasting rice genotypes corresponding to differential As accumulation during arsenate (As(V)) and arsenite (As(III)) exposures. The study was conducted on two contrasting As accumulating rice genotypes selected from 303 genotype accessions, in hydroponic conditions. Maximum As accumulation was up to 1181 μg g(-1) dw in the roots of high As accumulating genotype (HARG), and 89 μg g(-1) dw in low As accumulating genotype (LARG) under As(III) exposures. The inorganic As was correlated more significantly upon exposures to As(III) than As(V). In the presence of As(V) various antioxidant enzymes guiacol peroxidase (GPX), ascorbate peroxidase (APX) and superoxide dismutase (SOD) were highly stimulated in HARG. The stress responsive amino acids proline, cysteine, glycine, glutamic acid and methionine showed higher accumulation in HARG than LARG. A clear correlation was found between stress responsive amino acids, As accumulation and antioxidative response. The comparisons between the contrasting genotypes helped to determine the significance of antioxidants and specific amino acid response to As stress.
由于东南亚地区受污染地下水的灌溉，大米中含有致癌性砷（As）。本研究评估了在砷酸盐（As(V)）和亚砷酸盐（As(III)）暴露下，具有不同砷积累特性的对照水稻基因型的比较抗氧化特性和特定氨基酸积累。在水培条件下，从 303 个基因型中选择了两个具有不同砷积累特性的对照基因型进行了研究。在高砷积累基因型（HARG）的根中，砷的最大积累量高达 1181μg g(-1) dw，而在低砷积累基因型（LARG）中，砷的最大积累量为 89μg g(-1) dw。在暴露于 As(III)时，无机 As 的相关性比 As(V)更为显著。在存在 As(V)的情况下，HARG 中的几种抗氧化酶（如愈创木酚过氧化物酶（GPX）、抗坏血酸过氧化物酶（APX）和超氧化物歧化酶（SOD））被高度刺激。应激响应氨基酸脯氨酸、半胱氨酸、甘氨酸、谷氨酸和蛋氨酸在 HARG 中的积累量高于 LARG。发现应激响应氨基酸、As 积累和抗氧化反应之间存在明显的相关性。对照基因型之间的比较有助于确定抗氧化剂和特定氨基酸对 As 应激的响应的重要性。
